Study Links Sugar, Child Anxiety

Yale University medical researchers have found hormonal evidence to support the popular but controversial belief that sugar can provoke abnormal behavior in some children.

The physicians, who presented their preliminary findings Wednesday to the annual meeting of the Society for Pediatric Research in Anaheim, showed that a concentrated dose of sugar resulted in a dramatic increase in blood levels of adrenalin in children but not in adults.

In the 14 healthy children tested after being given a sugar dose equivalent to two frosted cupcakes for breakfast, adrenalin levels in the blood rose 10 times higher than they were before they ate the sweet.

No such dramatic rise in adrenalin was noted in the nine adults similarly tested, even though blood sugar levels in the adults were comparable to those in the children.

In the course of the five-hour test, nearly all the children complained of feeling weak and shaky, while only one adult had similar complaints.

Adrenalin, also known as epinephrine, is produced by the adrenal glands and is released in increased amounts when a person is under stress or threatened.

The results suggest that children experience a greater hormonal response to sugar than do adults, said the researchers, Dr. William Tamborlane, professor of pediatrics and director of the pediatric endocrinology division at Yale School of Medicine, and Dr. Timothy M. Jones, a visiting scientist from Perth, Australia.

Jones said the raised levels of adrenalin after a sugary meal could lead to anxiety, difficulty concentrating and crankiness.

``If a child is prone to have difficulty concentrating, the adrenalin response may tip the balance,`` Jones said.

Countless parents have described hyperactive, irritable or aggressive behavior in their children after the consumption of sugary foods or beverages. But various studies, both in normal children and in those diagnosed as hyperactive, have shown conflicting effects of sugar on the behavior. Most of the studies that involved disguised doses of sugar or artificial sweeteners found little or no difference in behavior after the consumption of foods containing those ingredients.

But few if any of these studies administered the test dose on an empty stomach and monitored the biochemical response.

The Yale researchers are planning another, more realistic, study of children who will be given a breakfast of orange juice and doughnuts.

Typically, an American child age 5 to 12 consumes 134 grams of sugar a day, the amount one would get by consuming a quart of milk, a 12-ounce soft drink, 4 ounces of orange juice, one apple, one plain doughnut and one chocolate bar.